We propose to study the electric dichroism (ED) of DNA and DNA-drug complexes. Our goals are to exhaustively study the ED of DNA and interpret the results to support or oppose the usual B-form X-ray structure of solution DNA. The limiting ED is given as delta epsilon/epsilon equals 3/2(3cos squared alpha-1) where delta epsilon/epsilon is the reduced electric dichroism and alpha is the angle between the dipole axis and the chromophoric transition moment. Since we have a considerable amount of transition moment directional information the angle alpha can often yield true structural parameters. By varying the wavelength of our measurements as well as the base composition of the DNA, we can determine and verify the angles of base tilt and dihedral twist for the DNA solution structure. The structure obtained will be compared to the X-ray structure as well as model of Levitt. Having characterized DNA we propose to study the binding of drugs to DNA in the light of the solution structure determined. We plan to examine the Ed of the complexes of Actinomycin D, Steffimycin B, Adriamycin, and Echinomycin with DNA. We will partition the ED signal into that due to the DNA and that due to the drug. The additivity of the ED signals will be verified. The ED of the drug will be used to determine if chromophores are oriented differently as an aid to determine drug conformation. We can also estimate the directions of the transition moments for the drug molecules by comparison of the dichroism of the bases. In essence we plan to use the DNA as an orientable matrix to study the small drug molecules by Ed.